Coral reef ecosystems are among the most diverse and productive ecosystems in the world. Additionally, many humans in tropical and subtropical coastal environments are completely dependent upon coral reefs for food, building materials, and protection of the coast from damaging waves. Coral reefs are also very fragile and delicately balanced systems that are easily disturbed by external forces such as anthropogenic influences. Current disturbances to coral reef ecosystems pal in comparison to changes that are predicted to occur as the result of global climate changes resulting from anthropogenic activities. Predicted increase in atmospheric temperatures are predicted to result in significant increases in sea level as the polar ice caps melt. Changes in global distributions of heat, both in the atmosphere and oceans, will also change wind patterns and ocean circulation patterns. The combined effects of these changes will impact tropical marine environments where coral reefs currently thrive. Prediction and perhaps mitigation of significant changes in coral reef environments must be based on an understanding of how coral reefs normally function and how coupled they are to the surrounding oceanic environment. Central to this understanding is the role that hydrodynamics, or water motion, plays in controlling the important physical and biological processes on coral reefs. Elucidating the role of hydrodynamic on the metabolism of the most productive component of coral reefs. Elucidating the role of hydrodynamics on the metabolism of the most productive component of coral reefs ecosystems (algal turfs) is the focus of a study funded by the National Science Foundation. The specific aims of this NIH Minority Biomedical Research Support proposal are: a) To gain a better understanding of the role of hydrodynamics and the coupling between physical and biological processes in coral reefs in order to predict the effects of human-induced global climate changes on these productive ecosystems. b) To involve minority students in the study of hydrodynamics, thereby giving the opportunity to study the principles of biophysics of fluids and diffusion that are equally applicable to animal circulation systems and are therefore of general interest. c) through the involvement of MBRS students, to attract minority students to the subfield of marine biology, where minorities are severely underrepresented. This MBRS project will allow the principal investigator to increase his level of participation in the NSF-funded project and devote additional time to training MBRS students in state- of-the-art approaches to the physiological ecology of coral reefs.